Improvement in snatch-blocks



O SPENCER. Snatch-Block.

Nb. 21 91.- Patented Aug. 19, 1879.

FIG. I. FIGJQ.

WITNESSES. INVENTUR.

N.FE\'ERS. PKOTO-UTHOGRAFHER. WASHINGTON D C.

UNITED; STATES PATENT Onnron COOPER SPENCER, OF PROVIDENCE, RHODE ISLAND.. 1

IMPROVEMENT IN SNATCH-BLOCKS.

Specification forming part of Letters Patent No. 218,691, dated August 19, 1879; application filed March 19, 1879.

To all whom it may concern:

Be it known that I, COOPER. SPENCER, of the city and county of Providence, and State of Rhode Island, have invented certain new and useful Improvements in Tackle-Blocks; and I do hereby declare that the following specilica tion, taken in connection with the accompanying drawings, forming a part ofthe same, is a full, clear, and exact description thereof.

The invention hereinafter described relates to the construction of tackle-blocks; and it consists in makinga metal snatch-block with duplicate cheeks or sides,"which can be cast from one pattern, mounting such checks on the sheave-axle so that they may be separated in parallel planes, and providing said cheeks with hooks or equivalent devices which engage each other laterally, furnish a means for quickly and conveniently attaching and detaching the block, and distribute the strain equally. on each cheek.

It alsoconsists in providing the hook portions of a block so constructed with mortises and dowels, which assist in preventing the cheeks from lateral movement when the block is closed, and also furnish a means by which said cheeks may be temporarily or permanently secured against separation if desired.

Snatch blocks as heretofore constructed have been mainly of two varieties-those whose checks are secured to each other at the bottom, and one cheek provided with a hinged flap, which can be turned down after the looking pin or hook has been removed, and a second variety, in which the checks are mounted on the sheave-axle and are separable in parallel planes.

As far. as I am aware, cast-metal snatchblocks have never been made with checks or sides one of which was the counterpart of the other. Such cheeks have been relatively dif ferently formed, andvarious constructions employed for securing them against separation after the block has been rove. This lack of uniformity in the cheeks and the character of the devices employed for securing said cheeks temporarily to each other have made snatchblocks comparatively expensive, particularly those made of cast metal, for the reason that a distinct pattern for each cheek has been required, and separate pieces in the form of precaution was taken to lash or otherwise treat said devices to prevent accidental detachment.

The objects, therefore, of my invention are, first, to furnish a snatch-block of simple and comparatively inexpensive construction, which can be easily attached and detached, and be securely held in position by the attaching devices without lashing or otherwise treating said devices; and, second, to furnish other means by which the cheeks of the block may be permanently secured against separation if desired.

Referring to the drawings, Figure 1 represents a front elevation of my improved snatchblook, the cheeks being closed. Fig. 2 shows the same with the cheeks separated to admit of the block being rove and attached.

The construction of my improved snatchblock will be understood by an examination of Figs. 1 and 2, in which A represents the sheave; B, the sheave-axle, and C the duplicate cheeks mounted on said axle so as to be separable in parallel planes. 4

Each check is provided with a hook, D, forming a part of such cheek, the said hooks furnishing a means for attaching theblock securely in position and causing the strain to be distributed equally on each side. These hooks are provided with dowels, as at d, and mortises, as at d, the dowels entering the mortises when the block is closed, and assisting to prevent the cheeks from lateral separation.

For the purpose of making a double-becket block, each cheek maybe supplied with a second hook, as shown by dotted lines in said figures, the hooks of each cheek engaging the hooks of the fellow cheek laterally.

The cheeks of a snatch block thus constructed can be cast from one pattern, the block will be simple and inexpensive in construction, can be easily attached, will not become accidentally detached, and no lashing of the hooks is necessary to secure the block in position.

For the purpose of securing the sides of the block against separation when desired the length of the dowels dis made greater than the depth of the mortises d, so that said dowels may be headed over, or a hole drilled in each and a pin inserted, the former method being preferable for permanently securing said sides together, and the latter for temporary purposes.

A tackle-block furnished with my improved attaching devices may be easily and quickly mounted in position, and will be secure against accidental detachment without the necessity of lashing.

Although in my improved snatch-block, as shown, the hooks D engage each other in a plane occupied by the axis of the sheave-axle, yet the said hooks may be arranged to engage each other in a plane at right angles to said axis,thedowels and mortises being dispensed with, and the engaging faces of the hooks being slightly corrugated if desired.

Having described my invention, what I claim, and desire to secure by Letters Patent, 1s-

1. A castrmetal snatch-block frame composed of two counterpart checks, 0 C, which are extended in the form of duplicate hook portions D D, and which can be produced from one pattern, as described, the said hook portions being arranged to engage each other laterally and furnish a means for directly attaching the frame in position, substantially as set forth.

2. The suatch'block herein described, havin g cheeks which are mounted on the sheave axle so as to be separable in parallel planes, and said cheeks provided with hook portions D D, which form a part of or are securely attached to said cheeks, engage each other laterally, and directly attach the block in position, substantially as described and shown.

3. In combination with the cheeks of a tackle-block, a hook or hooks forming a part of or securely attached to each cheek respectively, and provided with a dowel and mortise, which assist to prevent the cheeks of the block from lateral separation when said hooks are in contact, and furnish a means by which the said cheeks may be securely attached to each other, substantially as set forth.

COOPER SPENCER.

Witnesses:

EDSON SALISBURY J ONES, WM. A. OADY. 

